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A googol-to-one gear ratio [video]

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Re: A googol-to-one gear ratio [video]

#22

Why can't it spin faster?

Even if the first gear's teeth were moving at supersonic speeds, there still would not be any perceptible motion of the last 90 gears or so. If the first gear's teeth were moving at relativistic speeds, there would still be no apparent motion in about 80 of the gears. The speed of light is only about a million times higher than the speed of sound, and this contraption loses a factor of a million after six gears.

Re: A googol-to-one gear ratio [video]

#24

Earlier quoted context omitted.

In the hour-long video, from the start to the end, only the first seven gears move visibly, and the 8th moves maybe a pixel. You probably couldn't move anything past the 3rd or 4th gear with your hand, depending on how low-friction the bearings are, how strong you are, and how little you care about hurting your hand. You could attach a long lever to one, but that'll only get you one, maybe two gears further.

Yeah, but that's just an engineering problem.

> that's just an engineering problem

It's not - it's a physics problem - it reaches fundamental physical limits of the universe.

Re: A googol-to-one gear ratio [video]

#27

The original mentioned, Arthur Ganson's Machine with Concrete, is quite a bit more artistic. The end is cast in concrete. The idea is that there is a certain amount of energy lost as friction in each gear, per turn. If you calculate the gear ratios and how many turns of the earlier gears would be required to make the final gear move, even infinitesimally, the amount of energy lost becomes more than all the energy in…

Impressive but imho he could take it one step further and instead of concrete on the other end, he could rotate the gear in the opposite way.

Re: A googol-to-one gear ratio [video]

#28

The original mentioned, Arthur Ganson's Machine with Concrete, is quite a bit more artistic. The end is cast in concrete. The idea is that there is a certain amount of energy lost as friction in each gear, per turn. If you calculate the gear ratios and how many turns of the earlier gears would be required to make the final gear move, even infinitesimally, the amount of energy lost becomes more than all the energy in…

The concrete felt too on-the-nose to me.

The OP's gears are better laid out to illustrate the concept, and they let you think about what happens with the last gear instead of demonstrating it so... concretely.

Re: A googol-to-one gear ratio [video]

#29

Earlier quoted context omitted.

Yeah, but that's just an engineering problem.

> that's just an engineering problem It's not - it's a physics problem - it reaches fundamental physical limits of the universe.

Okay, time for me to go sit in a dark room and think for a bit.

Re: A googol-to-one gear ratio [video]

#30
post #27

The original mentioned, Arthur Ganson's Machine with Concrete, is quite a bit more artistic. The end is cast in concrete. The idea is that there is a certain amount of energy lost as friction in each gear, per turn. If you calculate the gear ratios and how many turns of the earlier gears would be required to make the final gear move, even infinitesimally, the amount of energy lost becomes more than all the energy in…

Impressive but imho he could take it one step further and instead of concrete on the other end, he could rotate the gear in the opposite way.

When all the slack has been rotated out, it would require a tremendous amount of force to rotate that last gear in reverse. After all, the system wants to amplify the gear speed from that end.
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